This invention relates to flammable compositions and more particularly to flammable compositions which include a fuel and an oxidizer, burn relatively fast, and form substantially non-gaseous residues.
A major application of flammable compositions is as a military weapon both against personnel and material. Materials, such as communication equipment and supplies are ignited by flammable compositions and rendered useless. Even heavy weapons such as tanks and artillery can be successfully attacked with flammable compositions due to the possible ignition of fuel and ammunition, destruction of sensitive essential parts and even volatilization or decomposition of lubricants.
In order for a flammable composition to be highly effective in use against personnel, it must meet the following criteria:
A. A large number of burning particles must be densely distributed over the target area to increase the probability of multiple hits; PA1 B. The burning time of the particles should not be more than approximately 10 seconds, the estimated maximum time span for the burning particles to be removed from the targets; PA1 C. The particles must be easily ignitable; and PA1 D. The caloric output and thus the temperature of the burning particles must be as high as possible, which implies that the reaction products must not be gases in order to minimize heat losses.
Currently used flammable compositions which are used as military weapons are gelled flammable liquids. Gelling agents (and sometimes ignition materials) are mixed with gasoline or similar readily combustible liquids or solutions to form one suitable flammable composition. A generic term for such flammable materials is Napalm.
For maximum efficiency against material, the Napalm gel, after impact, must break up into globules with burning times of up to 15 minutes. The huge fireballs which form initially upon impact from the combustion of finely divided gel look quite impressive but are, in themselves, rather ineffective.
Napalm gels are highly effective against materials, but when Napalm gels are used as anti-personnel weapons the gels are less effective because the burning globules, reaching temperatures between 900.degree. and 1000.degree. C will in most cases be removed by the attacked personnel from their bodies and clothes within 10 seconds or less, thus sustaining only superficial burns which require minimum medical attention. As a result, close to 99% of the chemical energy contained in the Napalm globules with their burning time of approximately 15 minutes is wasted.
Napalm-type flammable materials do not contain any oxidizers, their combustion depends solely on oxygen from the ambient air. When the oxygen in the immediate vicinity of the burning globules is consumed, fresh air has to move in to continue to support combustion. This, combined with the fact that combustion under these conditions can occur only at the surface of the globules, accounts for the long burning time. The combustion products are gases which, together with the simultaneously heated nitrogen of the air, remove a substantial part of the combustion heat from the target; this accounts for the relatively low, burning temperature.
Thus, the long burning time of Napalm-type material, combined with heat removal by the gaseous of the combustion products show clearly that Napalm does not meet all of the desired criteria for flammable compositions to be used as anti-personnel weapons.